The present invention concerns a transmission for a twin-screw extruder.
The two screws in extruders of this genus are slightly separated and rotate in the same or in opposite senses. The transmission's take-off shafts must accordingly also be close to each other and be rotated at the same torque. The purpose of the transmission is to reduce the speed of the motor, to convert and divide the torque, and to accommodate the axial forces that accompany the extrusion.
The housing of one known transmission of this genus (European Published Application 716 914) is divided into an intake half and an outtake half by a vertical sectional joint. The intake half accommodates a gear and the intake end of the distributor shafts. This approach allows a shorter transmission and housing. To facilitate assembly, the housing is divided along and at the level of each shaft, with the intake half including two and the outtake half three horizontal plane areas. The expense of machining the housing increases, and the precision of the transmission decreases, however, with the number of sectional joints.